Parts for your 1999 Ford Falcon-Oil seals

1999 Ford Falcon (AU) oil seals: what they do and how to keep them happy

Oil seals are definitely used and relevant on the 1999 Ford Falcon (AU series). Authoritative sources including the Ford AU Falcon Workshop Manual (1998–2002), the Ford Microcat Electronic Parts Catalogue, and the Gregory’s Ford Falcon AU 1998–2002 Service and Repair Manual all specify crankshaft front and rear main seals, camshaft seals, automatic transmission input/output and selector shaft seals, differential pinion and axle seals, and power steering rack and pump seals for this model.

On an AU Falcon, oil seals keep engine oil, ATF and diff oil where they belong, while keeping dust and water out. Over time, heat cycles, age and crankcase pressure can harden the rubber and wear the sealing lips, leading to weeps or drips. They’re not a routine replacement item, but they’re well worth checking whenever the car’s in for a service or related repairs.

• Typical seals on the AU: front crankshaft (behind the harmonic balancer), rear main (between engine and gearbox), camshaft front seal, timing cover and sump seals, auto trans front pump and output shaft seals, diff pinion and axle seals, and power steering rack/pump seals.
• Common signs: oil mist around the crank pulley, oil in the bellhousing area (rear main), ATF at the tailshaft or selector, diff oil flung around the pinion flange, or a burnt oil smell on the exhaust.

Good servicing habits help seals last: keep oil and ATF at the correct grade and level, change fluids on time, and make sure the PCV/breather system isn’t blocked so crankcase pressure doesn’t push past seals. During services, a quick look under the bonnet and under the car for fresh oil traces saves headaches later.

If replacement’s on the cards, it pays to plan the job around other work. A rear main, for example, is easiest when the gearbox is already out for a clutch or flexplate job. Use quality seals, lightly oil the lip before fitment, and press them square with the correct driver. Inspect the shaft surfaces, if there’s a groove, consider a sleeve. For diff pinion seals, mark the nut or set preload to spec rather than guessing. And if an AU’s throwing repeated leaks, check for overfill, blocked breathers or a worn balancer snout before blaming the new seal.

Done properly, fresh seals mean a tidier driveway, steadier fluid levels and less muck building up around the engine bay and underbody.

Popular questions about 1999 Ford Falcon oil seals

Where do oil-seal leaks usually show up on a 1999 Ford Falcon?
Owners often spot weeping at the front crank seal behind the harmonic balancer, or oil tracking from the bellhousing area if the rear main is tired. On autos, red ATF can appear at the output shaft or selector shaft. At the rear, a diff pinion seal can sling oil onto the tailshaft and underbody, and axle seals can dampen the brake backing plates.

If the leak appears high on the engine, also consider rocker cover and timing cover gaskets before condemning a seal.

Do oil seals need routine replacement on an AU Falcon?
They’re not a scheduled service item. Seals are replaced when they leak or when access is easy during related work (like a clutch change, timing cover service or tailshaft removal). Regular fluid changes, correct grades and a healthy PCV system go a long way to keeping seals happy.

Any sign of fresh oil, ATF or diff oil should be checked promptly, small weeps can become big messes, and contaminated belts or brake linings are no fun.

Can a home mechanic replace the rear main seal?
It’s possible but not a quick driveway job. The gearbox (or auto and flexplate) must come out, and care is needed to avoid damaging the new seal or the crank surface. Many DIYers choose to bundle it with a clutch replacement or major trans work to save time and labour.

Front crank, cam, diff pinion and output shaft seals are generally more approachable for competent home mechanics with the right tools and torque specs.